Fluorine containing sialyl Lewis X derivatives and synthetic intermediates thereof

ABSTRACT

A sialyl Lewis X derivative represented by the general formula: ##STR1## in which a hydroxyl group at the 2 position of fucose is replaced with a fluorine atom, and a synthetic intermediate therefor are provided.

The present application is the U.S. National Phase entry under 35 U.S.C.§371, of PCT/JP96/02250 filed on Aug. 8, 1996.

FIELD OF THE INVENTION

The present invention relates to sialyl Lewis X derivatives in which thehydroxy group at the 2 position of fucose is substituted with fluorine,and synthetic intermediates thereof and a process for the preparationthereof. These derivatives are useful in the fields of medical drugs,for example, in the fields of the treatment and prophylaxis ofinflammation and thrombopoiesis associated with inflammation, asthma,rheumatism, immunological diseases and cancers.

BACKGROUND OF THE INVENTION

Sialyl Lewis X sugar chain, which is an oligosaccharide containingfucose, has recently attracted attention since it may be involved inhoming phenomena in which upon inflammation leucocytes interact withendotheliocytes of blood vessels and bleed out of the blood vessels.Some of the homing phenomena start with interaction of the sialyl LewisX oligosaccharide with a lectin-like cell adhesive molecule calledselectin. Therefore, if the sialyl Lewis X oligosaccharide could be usedas a selectin binding inhibitor, acute inflammations depending uponneutrophils (one of leucocytes) and upon selectin would be expected tobe suppressed. In fact, is was shown by a group of Michigan Universitythat acute pulmonic inflammation caused experimentally in rat usingcobra venom factor was relieved by administration of the sialyl Lewis Xsugar chain (M. S. Mulligan, et al., Nature, 364, 149 (1993)).

Thus, synthesis of various derivatives, for example, derivatives (3) (S.Hakomori, et al., WO 92/19632 (1992)) and (4) (W. Stahl, et al., Angew.Chem. Int. Ed. Engl., 33, 2096 (1994)) in which hydrogen atoms orhydroxy groups of Lewis X ganglioside (1) or sialyl Lewis X ganglioside(2) are replaced by fluorine, were studied. However, it is consideredthat these derivatives would lose their activity immediately sincefucose is released due to α-1,3-fucosidase.

Accordingly, we have made an attempt to create a sialyl Lewis X havingpotent selectin adhesion inhibiting activity and metabolic stability. Assuch a candidate compound, a derivative of sialyl Lewis X in which ahydroxy group at the 2 position of fucose is substituted with a fluorineatom was designed. There was no method for introducing such afluorine-containing fucose into the sugar chain streo- andposition-specifically. ##STR2##

Sialyl Lewis X derivatives are known to be ligand moieties of E and Lselectins having an action as a cell adhesion molecule, and areimportant compounds having a function as a recognition element of cellsspecifically expressing these selecting. It is useful to synthesizesialyl Lewis X derivatives modified with fluorine in an organic chemicalmanner so as to investigate the effects of chemical structures on theexpression of their activity. It is also considered that such afluorine-substituted sialyl Lewis X could be applicable to developmentof practical medical drugs and clinic.

Therefore, it is very meaningful to elucidate the above described sialylLewis X derivatives and to provide them in practical amounts.

SUMMARY OF THE INVENTION

It is an object of the present invention to provide newfluorine-containing sialyl Lewis X derivatives which are expected to bethe above described drugs, synthetic intermediates thereof and a methodof their preparation.

The present inventor has studied for the purpose of synthesizing sialylLewis X analogs in which a hydroxy group at the 2 position of fucose ischemically modified with fluorine and, as a result, succeeded in thesynthesis of such analogs leading to the present invention.

Accordingly, the present invention relates to a sialyl Lewis Xderivative represented by the general formula (I-1): ##STR3## wherein Rdenotes an aliphatic acyl group having 2 to 6 carbon atoms; R¹ denotes ahydrogen atom or a lower alkyl group having 1 to 5 carbon atoms; R²⁰,R³⁰ and R⁵ independently denote a hydrogen atom, an aliphatic acyl grouphaving 2 to 6 carbon atoms, or an aromatic acyl group having 7 to 13carbon atoms; R⁴ denotes a hydroxy group, an aliphatic acylamino grouphaving 2 to 6 carbon atoms, an aromatic acylamino group having 7 to 13carbon atoms, an aliphatic acyloxy group having 2 to 6 carbon atoms, oran aromatic acyloxy group having 7 to 13 carbon atoms; Ra denotes astraight or branched, saturated or unsaturated, aliphatic group having 1to 30 carbon atoms; Me denotes a methyl group; and n denotes an integerof 0 to 20, provided that when R¹ is a hydrogen atom, R²⁰, R³⁰ and R⁵all denote a hydrogen atom; and R⁴ denotes a hydroxy group, or analiphatic or aromatic acylamino group; or when R¹ is a lower alkylgroup, R²⁰, R³⁰ and R⁵ denote an aliphatic or aromatic acyl group; andR⁴ denotes an aliphatic or aromatic acylamino group, or an aliphatic oraromatic acyloxy group.

The present invention also relates to a compound represented by thegeneral formula (I-2): ##STR4## wherein R, R¹, R²⁰, R³⁰, R⁴, R⁵, Me andn are as defined above; and R¹⁰ denotes N₃ or NH₂ group, provided thatwhen R¹ is a hydrogen atom, R²⁰, R³⁰ and R⁵ all denote a hydrogen atom;and R⁴ denotes a hydroxy group, or an aliphatic or aromatic acylaminogroup; or when R¹ is a lower alkyl group, R²⁰, R³⁰ and R⁵ denote analiphatic or aromatic acyl group; and R⁴ denotes an aliphatic oraromatic acylamino group, or an aliphatic or aromatic acyloxy group,which compound is a synthetic intermediate of the compound representedby the general formula (I-1).

The present invention also relates to a compound represented by thegeneral formula (II): ##STR5## wherein R, R¹, R²⁰, R³⁰, R⁴ and Me are asdefined above; and X denotes a hydroxy group, a fluorine atom, athioalkyl group having 1 to 5 carbon atoms, a thioaryl group having 6 to12 carbon atoms, or a --OC(NH)CCl₃ group, provided that when R¹ is ahydrogen atom, R²⁰ and R³⁰ both denote a hydrogen atom; R⁴ denotes ahydroxy group, or an aliphatic or aromatic acylamino group; and Xdenotes a hyroxy group; or when R¹ is a lower alkyl group, R²⁰ and R³⁰denote an aliphatic or aromatic acyl group; R⁴ denotes an aliphatic oraromatic acylamino group, or an aliphatic or aromatic acyloxy group; andX denotes a fluorine atom, a thioalkyl group, a thioaryl group or a--OC(NH)CCl₃ group, which compound is a synthetic intermediate of thecompound represented by the general formula (I-2).

Further, the present invention relates to a compound represented by thegeneral formula (III): ##STR6## wherein R, R¹, R⁴ and Me are as definedabove; R²¹ and R³¹ independently denote a hydrogen atom, anunsubstituted or substituted phenylmethyl group having 7 to 13 carbonatoms, an aliphatic acyl group having 2 to 6 carbon atoms, or anaromatic acyl group having 7 to 13 carbon atoms; and TAS denotes atrialkylsilyl in which the alkyl group has 1 to 7 carbon atoms, providedthat when R¹ is a hydrogen atom, R²¹ and R³¹ both denote a hydrogenatom; and R⁴ denotes a hydroxy group, or an aliphatic or aromaticacylamino group; or when R¹ is a lower alkyl group, R²¹ and R³¹ denotean unsubstituted or substituted phenylmethyl group, or an aliphatic oraromatic acyl group; and R⁴ denotes an aliphatic or aromatic acylaminogroup, or an aliphatic or aromatic acyloxy group.

Further, the present invention also relates to a compound represented bythe general formula (IV): ##STR7## wherein R²¹, R⁴ and TAS are asdefined above, provided that when R²¹ is a hydrogen atom, R⁴ denotes ahydroxy group, or an aliphatic or aromatic acylamino group; or when R²¹is an aliphatic or aromatic acyl group, or an unsubstituted orsubstituted phenylmethyl group, R⁴ denotes an aliphatic or aromaticacylamino group, or an aliphatic or aromatic acyloxy group.

The present invention further relates to a compound represented by thegeneral formula (V): ##STR8## wherein R²¹, R⁴ and TAS are as definedabove and Ph denotes an unsubstituted or substituted phenyl group,provided that when R²¹ is a hydrogen atom, R⁴ denotes a hydroxy group,or an aliphatic or aromatic acylamino group; or when R²¹ is anunsubstituted or substituted phenylmethyl group, or an aliphatic oraromatic acyl group, R⁴ denotes an aliphatic or aromatic acylaminogroup, or an aliphatic or aromatic acyloxy group, which compound is aprecursor of the compound represented by the general formula (IV).

The present invention still further relates to a compound represented bythe general formula (VI): ##STR9## wherein R⁶ denotes an unsubstitutedor substituted phenylmethyl group; and R⁹ denotes a lower alkyl grouphaving 1 to 5 carbon atoms, or an unsubstituted or substituted phenylgroup having 6 to 12 carbon atoms.

The present invention also relates to a compound represented by thegeneral formula (VII): ##STR10## wherein R¹¹ denotes a lower substitutedalkyl group having 1 to 10 carbon atoms, or an unsubstituted orsubstituted phenylmethyl group having 7 to 13 carbon atoms; and R⁷denotes a hydrogen atom, an unsubstituted or substituted phenylmethylgroup, an aliphatic acyl group having 2 to 6 carbon atoms or an aromaticacyl group having 7 to 13 carbon atoms.

The present invention also relates to a compound represented by thegeneral formula (VIII): ##STR11## wherein R⁸ denotes an aliphatic acylgroup having 2 to 6 carbon atoms or an aromatic acyl group having 7 to13 carbon atoms.

PREFERRED EMBODIMENTS OF THE INVENTION

Methods for preparing the sialyl Lewis X derivatives of the presentinvention will be illustratively described hereinafter.

As seen from the chemical structural formula (I-1), the fluorinesubstituted sialyl Lewis X derivative of the present invention iscomposed of a sialylgalactose moiety, a fucose moiety, a glucosaminelactose moiety and a ceramide moiety.

At first, the fucose moiety of the fluorine substituted sialyl Lewis Xderivative is synthesized according to the following Reaction Scheme 1:##STR12##

In the formulae, wherein R⁸ denotes an aliphatic or aromatic acyl group;R¹¹ denotes a lower substituted alkyl group, or an unsubstituted orsubstituted phenylmethyl group; R⁶ denotes an unsubstituted orsubstituted phenylmethyl group; and R⁹ denotes a lower alkyl group, oran unsubstituted or substituted phenyl group.

Thus, a starting material,3,4-di-O-acyl-2-deoxy-2-fluoro-α-L-fucopyranosyl fluoride (Compound 1A)is treated with a reagent such as hydrogen bromide/acetic acid, orphosphorus tribromide or phosphorous pentabromide, resulting in theformation of a compound of the general formula (VIII) in which the 1position is brominated.

Compound 1A may be synthesized from L-fucopyranose tetracetate accordingto the method as described in Tetrahedron, 35, 2551-2554 (1979).Examples of R⁸ include acetyl, propionyl, pivaloyl, sec-butyroyl,benzoyl, chlorobenzoyl and methoxybenzoyl. Introduction of such group inCompound 1A instead of acetyl group may be previously done in aconventional manner when synthesizing Compound 1A.

A compound of the general formula (VIII) may then be reacted with alower substituted alcohol, benzyl alcohol or substituted phenylmethylalcohol in the presence of, e.g., a silver salt to give a compound ofthe general formula (VII-1). Lower substituted alcohols used includetrialkylsilylethyl alcohols in which the alkyl group may be methyl,ethyl, propyl, butyl, pentyl, hexyl, heptyl, octyl, nonanyl or decanyl,and 4-pentenylalcohol. Substituted phenylmethyl alcohols include4-methoxybenzyl alcohol, 4-acetamidebenzyl alcohol, 4-nitrobenzylalcohol, 4-chlorobenzyl alcohol or 4-bromobenzyl alcohol.

Then, the acyl type protective groups of the compound of the generalformula (VII-1) are converted into benzyl type protective groups. Thus,the treatment of the compound of the general formula (VII-1) with sodiummethoxide in methanol or sodium ethoxide in ethanol removes the acyltype protective group resulting in a compound of the general formula(VII-2), which is then protected with a desired protective group to givea compound of the general formula (VII-3).

Thus, a compound of the general formula (VII-2) is reacted with a benzylhalide or substituted phenylmethyl halide in the presence of a base suchas sodium hydride, triethylamine, or an unsubstituted or substitutedpyridine to convert into an unsubstituted or substituted phenylmethylether. The substituted phenylmethyls include 4-methoxybenzyl,4-acetamidebenzyl, 4-nitrobenzyl, 4-chlorobenzyl and 4-bromobenzyl.

The --OR¹¹ group in the compound of the general formula (VII-3) is thenconverted through an acetyl (--OAc) group into a SR⁹ group. Forinstance, when R¹¹ is a trialkylsilylethyl group, acetylation of thecompound of the general formula (VII-3) is carried out with aceticanhydride in the presence of a Lewis acid such as borontrifluoride-ether complex, followed by treatment with an alkylthioatingagent such as an alkylmercaptan or (alkylthio)trimethylsilane, or anunsubstituted or substituted thiophenol to give a compound of thegeneral formula (VI).

When R¹¹ is an unsubstituted or substituted phenylmethyl group, forexample, 4-methoxybenzyl group, the compound of the general formula (VI)is prepared by selectively removing the protective group at the 1position by means of DDQ (2,3-dichloro-5,6-dicyano-1,4-benzoquinone),followed by acetylation with acetic anhydride, and treatment with analkylthioating agent such as an alkylmercaptan or(alkylthio)trimethylsilane, or an unsubstituted or substitutedthiophenol.

A preferred embodiment for precontaining fucose containing fucosederivative of the general formula (VI) is shown in the followingReaction Scheme 2: ##STR13##

In the formulae, Me denotes a methyl group, Ac denotes an acetyl group,and Bn denotes a benzyl group.

The starting material,3,4-di-O-acetyl-2-deoxy-2-fluoro-α-L-fucopyranosyl fluoride (Compound 1)is treated with hydrogen bromide/acetic acid to convert it into Compound2 in which the 1 position is brominated. Compound 2 is reacted withtrimethylsilyl ethanol in the presence of a silver salt to yieldCompound 3. Compound 3 is deprotected to yield Compound 4, from whichCompound 5 is then derived. Compound 5 is further reacted with aceticanhydride at -30 to 0° C. for 3 hours in the presence borontrifluoride-ether complex to yield Compound 6. Compound (X) included inthe general formula (VI) is obtained by reacting Compound 6 with borontrifluoride-ether complex and (methylthio)trimethylsilane.

As shown in Reaction Scheme 3, the thus obtained fucose derivative ofthe general formula (VI) is condensed with a glucosamine lactosederivative (Compound 7) to obtain a condensed compound. The condensedcompound is reduced to a compound of the general formula (IV-1)optionally after changing protective groups for hydrogen groups. Thereduced compound is then condensed with a sialyl galactose derivative ofthe general formula (XIII) to give a compound of the general formula(III-1).

Compound 7 and the compound of the general formula (XIII) may easily besynthesized according to a method similar to that described inCarbohydrate Research, 200, 269-285 (1990). ##STR14##

In the above formulae, TAS denotes a trialkylsilyl group; Ph denotes anunsubstituted or substituted phenyl group; R^(4') denotes an aliphaticor aromatic acyloxy group, or an aliphatic or aromatic acylamino group;R^(21') and R^(31') independently denote an unsubstituted or substitutedphenylmethyl group, or an aliphatic or aromatic acyl group; R denotes analiphatic acyl group; R^(1') denotes a lower alkyl group; and R⁶, R⁹, Meand Bn are as defined above.

A compound of the general formula (VI) is condensed with Compound 7 inan inert solvent such as benzene, toluene, methylene chloride or mixturethereof in the presence of an appropriate glycosylation accelerator suchas N-iodosuccinimide/tetrabutyl ammonium triflate, ordimethyl(methylthio)sulfonium triflate, or N-bromosuccinimide/silvertrifluoromethanesulfonate to give a compound of the general formula(V-1).

Compound 7 may be easily synthesized according to a method similar tothat described in Carbohydrate Research, 200, 269-285 (1990).

The protective groups for hydroxy groups in the resultant compound ofthe general formula (V-1) may be changed to other desired protectivegroups. For example, the compound (V-1) may be subjected to catalyticreduction under hydrogen atmosphere to remove the protective groups forhydroxy groups to replace them by hydrogen atoms. A substitutedphenylmethyl group different from the removed protective group, such as4-methoxybenzyl, 4-acetamidebenzyl, 4-nitrobenzyl, 4-chlorobenzyl or4-bromobenzyl, can be introduced in the presence of a base such assodium hydride, triethylamine, or an unsubstituted or substitutedpyridine. Alternatively, after the hydroxy-protective groups arereplaced with hydrogen atoms as described above, an aliphatic oraromatic acyl group, such as acetyl, propionyl, pivaloyl, sec-butyroyl,benzoyl, chlorobenzoyl or 4-methoxybenzoyl, may be introduced by thereaction with an acylating agent such as an acyl halide or acidanhydride in the presence of a base such as sodium hydride,triethylamine, or an unsubstituted or substituted pyridine. The alkylgroups in the trialkylsilyl group may be identical with or differentfrom each other and include methyl, ethyl, propyl, butyl, pentyl, hexyl,heptyl, octyl, nonanyl or decanyl. Thus, a compound of the generalformula (V) is obtained.

Then, the cyclic benzylidene moiety in the compound of the generalformula (V-2) is reduced with a metal hydride such as sodiumborohydride, sodium cyanoborohydride, lithium aluminium hydride,borane-trimethylamine or triethylsilane in an inert solvent such astetrahydrofuran or ether to give a compound of the general formula(IV-1).

The group R^(21') in the compound of the general formula IV-1 can beremoved. When R^(21') is an aliphatic or aromatic acyl group, it may bereplaced with a hydrogen atom by treating the compound with sodiummethoxide in methanol or sodium ethoxide in ethanol. When R^(21') is anunsubstituted or substituted phenylmethyl group, it may be removed bycatalytic reduction of the compound under hydrogen atmosphere. WhenR^(4') is an aliphatic or aromatic acyloxy group, it may be convertedinto a hydroxy group by treating the compound with sodium methoxide inmethanol or sodium ethoxide in ethanol. Thus, a compound of the generalformula (IV) may be obtained.

A compound of the general formula (IV-1) is condensed with a compound ofthe general formula (XIII) to give a compound of the general formula(III-1). That is, a compound of the general formula (IV-1) is condensedwith a compound of the general formula (XIII) in an inert solvent suchas benzene, toluene, methylene chloride or mixture thereof in thepresence of an appropriate glycosylation promotor such asN-iodosuccinimide/tetrabutyl ammonium triflate, dimethyl(methylthio)sulfonium triflate, or N-bromosuccinimide/silvertrifluoromethanesulfonate to give a compound of the general formula(III-1).

The compound of the general formula (XIII) ma y be easily synthesizedaccording to a meth of similar to that described in CarbohydrateResearch, 200, 269-285 (1990).

When in the compound of the general formula (III-1) R¹ is a lower alkylgroup, R^(21') and R^(31') are aliphatic or aromatic acyl groups, andR^(4') is an aliphatic or aromatic acyloxy group, these protectivegroups can be converted to hydrogen atoms by the treatment of thecompound with sodium methoxide in methanol or sodium ethoxide inethanol. When R^(21') and R^(31') is unsubstituted or substitutedphenylmethyl groups, R¹ is a lower alkyl group, and R⁴ is an aliphaticor aromatic acylamino group, R²¹ and R³¹ can be removed by catalyticreduction of the compound under hydrogen atmosphere. Further, analiphatic or aromatic acyl group, such as acetyl, propionyl, pivaloyl,sec-butyloyl, benzoyl, chlorobenzoyl or methoxybenzoyl, may beintroduced by the reaction with an acylating agent such as an acylhalide or acid anhydride in the presence of a base such as sodiumhydride, triethylamine or an unsubstituted or substituted pyridine.Thus, a compound of the general formula (III) is obtained.

A preferred embodiment of for preparing a compound of the generalformula (III) is shown in the following Reaction Scheme 4. ##STR15##

As shown in Scheme 4, the thiomethyl compound (X) is reacted withCompound 7 in an inert solvent such as benzene, toluene, methylenechloride or mixture thereof in the presence of an appropriateglycosylation promotor, such as N-iodosuccinimide/tetrabutylammoniumtriflate or dimethyl(methylthio)sulfonium triflate at 0° C. for 2 to 3hours to give Compound 8. The reduction of the benzylidene moiety inglucosamine of the compound results in Compound 9. The reduction may becompleted with the use of an appropriate reducing agent such as sodiumboron hydrocyanide, borane-trimethylamine or triethylsilane in an inertsolvent such as tetrahydrofuran or ether at 0° to 30° C. within 2 hours.Compound 9,whose hydroxy groups are all protected except the hydroxygroup at the 4 position of the glucosamine moiety, is linked to asialylgalactose (Compound 10) to give Compound 11.

As shown in Reaction Scheme 5, a trialkylsilylethyl group is removedfrom the compound of the general formula (III-1) (when the compound hasbenzyl type protective groups, they should be converted into acyl typeprotective groups) to give a detrialkylsilylethylated compound. Thecompound is activated to obtain a compound, which is then condensed witha sphingosine derivative of the general formula (XIV) to yield acompound of the general formula (I-21). ##STR16##

In the formulae, R^(20'), R^(30') and R^(5') denote aliphatic oraromatic acyl groups; R¹² denotes N₃, NH₂ or NHCORa group in which Radenotes a saturated or unsaturated alkyl group; n denotes an integer of0 to 20; X denotes a hydroxy group, a fluorine atom, a thioalkyl group,a thioaryl group or --OC(NH)CCl₃ group; and R, R^(1'), R^(4') and TASare as defined above.

Removal of the trialkylsilylethyl group is carried out by treating acompound of the general formula (III-2) with a Lewis acid, such astrifluoroacetic acid or boron trifluoride-ether complex.

The thus obtained compound of the general formula (II-1) wherein X is ahydroxy group may be subjected to treatment with diethylaminosulfurtrifluoride (DAST), acetylation with acetic anhydride followed bytreatment with an alkylthiotrimethylsilane in the presence of a Lewisacid, acetylation with acetic anhydride followed by treatment with anaromatic mercaptan in the presence of a Lewis acid, or treatment withtrichloroacetonitrile (CCl₃ CN) in the presence of 1,8-diazabicyclo5.4.0!undeca-7-ene (DBU) to yield a compound of the general formula(II-1) in which X is converted into a fluorine atom, a thioalkyl group,a thioaryl group, or trichloroacetoimidate --OC(NH)CCl₃ !, respectively.

Finally, a compound of the general formula (II-1) is condensed with asphingosine derivative of the general formula (XIV) in the presence ofvarious glycosylation promotor such as boron trifluoride-ether complex,trialkylsilyl trifluoromethanesulfonate,N-iodosuccinimide/tetrabutylammonium triflate,dimethyl(methylthio)sulfonium triflate, tin (II) chloride/silverperchlorate or zirconocene/silver trifluoromethanesulfonate to yield acompound of the general formula (I-21).

The compound of the general formula (XIV) can be easily obtained bysynthesizing azide sphingosine according to the method described inCarbohydrate Research, 202, 177-191 (1990), protecting a primary hydroxygroup at the 1 position with an appropriate protective group such astriphenylmethyl group, protecting a hydroxy group at the 3 position in aconventional manner using, e.g. benzoyl chloride, and deprotecting theposition 1 by means of, e.g. boron trifluoride-ether complex.

As shown in Scheme 6, when R¹⁰ in the sphingosine moiety of the compoundof the general formula (I-21) is an azide group, the azide group can beselectively reduced (for example, with hydrogen sulfide) and the reducedcompound is reacted with a desired carboxylic acid in the presence of adehydrating condensation agent such as 1,2-dicyclohexylcarbodiimide(DCC) or 1-ethyl-3-(3-dimethylaminopropyl)carbodiimide (WSC) to obtain afully-protected, fluorine substituted sialyl Lewis X ganglioside (I-11).##STR17##

In the formulae, Ra denotes a saturated or unsaturated aliphatic group;and R, R^(1'), R^(20'), R^(30'), R^(4'), R^(5') and n are as definedabove.

De-O-acylation under alkaline conditions such as sodiummethoxide-methanol or sodium ethoxide-ethanol and hydrolysis ofCOOR^(1') group may yield a fluorine substituted sialyl Lewis Xganglioside of the general formula (IX), i.e., a compound of the generalformula (I-1) in which R¹, R²⁰, R³⁰ and R⁵ are hydrogen atoms and R⁴ isa hydroxy or acetylamino group. ##STR18##

A preferred embodiment is shown in the following Reaction Scheme 7.##STR19##

The benzyl group of Compound 11 is removed by catalytic reduction andthe resulting free hydroxy group is acetylated to yield Compound 12included in the general formula (II). The removal of trimethylsilylethylgroup at the 2 position of glucose in Compound 12 by the action oftrifluoroacetic acid gives Compound 13 included in the general formula(II). Compound 13 is treated with 1,8-diazabicyclo 5.4.0!undeca-7-ene(DBU) and trichloroacetonitrile (CCl₃ CN) to yiled Compound 14 includedin the general formula (II). Then, Compound 14 is treated with borontrifluoride ether complex in the presence of the azide sphingosinederivative (Compound A) to give Compound 15 included in the generalformula (I). The azide group of Compound 15 is then reduced withhydrogen sulfide gas followed by condensation with tetracosanoic acid inthe presence of a dehydrating condensation agent such as1-ethyl-3-(3-dimethylaminopropyl)carbodiimide hydrochloride to giveCompound 16. Compound 16 is then deprotected to give the desiredfluorine substituted sialyl Lewis X derivative, Compound (IX). Thereducing agent used to reduce said azide group is not limited tohydrogen sulfide, but includes any reducing agent which can reduce anazide group, does not reduce a double bond and does not release an acylprotective group. This reaction process is as shown in Reaction Scheme3.

The compounds of the present invention are expected to have selectinadhesion inhibiting activity and metabolic stability and, accordingly,to be capable of inhibiting neutrophils (one kind ofleucocytes)-dependent and selectin-dependent acute inflammation and tobe useful for the treatment and prevention of inflammation, andthrombopoiesis associated with inflammation, asthma, rheumatism,immunological diseases and cancers.

The present invention will be described by way of examples but is neverlimited thereto.

EXAMPLES Example 1 Synthesis of3,4-di-O-acetyl-2-deoxy-2-fluoro-α-L-fucopyranosyl bromide (referred toas Compound 2 hereinafter).

Compound 1 (0.300 g, 1.19 mmol) was dissolved in 0.7 ml of a mixedsolvent of acetic acid:acetic anhydride (2:1). The solution was cooledwith ice-water, and 1.35 ml (281 mmol) of a 33% solution of hydrogenbromide and acetic acid (Merck) was added thereto at 10° C. The reactionmixture was sealed, removed from the ice bath and stirred at an internaltemperature of 20° to 25° C. for 24 hours. The reaction mixture wasdiluted with dichloromethane and washed with cooling water, a saturatedaqueous sodium bicarbonate, and cooling water, successively. Afterdrying over sodium sulfate, vacuum concentration gave 0.364 g (yield:97.7%) of Compound 2.

C₁₀ H₁₄ O₅ BrF (313.12)

¹ H-NMR (CDCl₃ ; TMS): δ6.61 (d, 1H, J₁,₂ =4.2 Hz, H-1), 5.48 (dd, 1H,J₂,₃ =10.0 Hz, 1H, J₃,₄ =3.4 Hz, H-3), 5.38 (dd, 1H, J₃,₄ =3.4 Hz, J₄,₅=1.0 Hz, H-4), 4.74 (ddd, 1H, J_(F),₂ =50.5 Hz, J₁,₂ =4.2 Hz, J₂,₃ =10.0Hz, H-2), 4.44 (m, 1H, H-5), 2.17, 2.07 (2s, 6H, 2AcO), 1.22 (d, 3H,J₅,₆ =6.5 Hz, H-6).

¹⁹ F-NMR (CDCl₃ ; CFCl₃): δ-195 (ddd, J_(F),_(2H) =50.5 Hz, J_(F),_(3H)=9.4 Hz, J_(F),_(1H) =3.0 Hz)

Example 2 Synthesis of 2-(trimethylsilyl)ethyl3,4-di-O-acetyl-2-deoxy-2-fluoro-β-L-fucopyranoside (referred to asCompound 3 hereinafter).

Compound 2 (0.364 g, 1.16 mmol) was dissolved in 2 ml of anhydrousdichloromethane and 180 mg of activated Molecular Sieve 4 Å was addedthereto. The mixture was stirred under argon atmosphere for 1 hour(Mixture A). On the other hand, 0.16 ml (1.12 mmol) of2-(trimethylsilyl)ethanol, 0.130 g (0.63 mmol) of silver perchlorate and0.170 g (0.62 mmol) of silver carbonate were mixed with 1 ml ofanhydrous dichloromethane under argon atmosphere, and 180 mg ofactivated Molecular Sieve 4 Å was added to the mixture followed bystirring it at room temperature for 2 hours while shielding from light(Mixture B). Both mixtures were cooled with ice, and Mixture A was addedto Mixture B. The resulting mixture was heated to room temperature whileshielding from light and stirred for 12 hours. Insoluble materials werefiltered out and washed with dichloromethane. The filtrate and washingliquids were combined, washed with 5% aqueous sodium carbonate solutionand dried over sodium sulfate. After vacuum concentration of solvents,the residue was subjected to flash chlromatography with an eluent ofn-hexane:ethyl acetate (6:1) to give Compound 3 (277 mg, 68.0%).

C₁₅ H₂₇ O₆ FSi (350.47)

melting point: 48°-50° C.

α!_(D) ²⁴ =-26.4° (c 1.0, CHCl₃)

IR^(KBr) _(max) cm ⁻¹ : 1750, 1270 (ester), 870, 840 (Me₃ Si),

¹ H-NMR (CDCl₃ ; TMS): δ5.26 (ddd, 1H, J₃,₄ =J_(F),₄ =2.7 Hz, J₄,₅ =1.0Hz, H-4), 5.09 (ddd, 1H, J_(F),₃ =14 Hz, J₂,₃ =9.7 Hz, J₃,₄ =2.7 Hz,H-3), 4.53 (d, 1H, J₁,₂ =7.7 Hz, H-1), 4.45 (ddd, 1H, J_(F),₂ =44 Hz,J₂,₃ =9.7 Hz, J₁,₂ =7.7 Hz, H-2), 4.03 (m, 1H, CHCH₂ Si), 3.82 (dq, 1H,J₅,₆ =6.5 Hz, J₄,₅ =1.0 Hz, H-5), 3.60 (m, 1H, CHCH₂ Si), 2.05, 2.15 (s,6H, 2AcO), 1.21 (d, 3H, J₅,₆ =6.5 Hz, H-6), 1.04 (m, 2H, CH₂ CH₂ SiMe₃).

¹⁹ F-NMR (CDCl₃ ; CFCl₃): δ-207 (dd, 1F, J_(F),_(2H) =44 Hz, J_(F),_(3H)=14 Hz, 2-F),

Mass spectrometry: m/z calculated for C₁₅ H₂₇ O₆ FSi 351.1639 (M+H);found 351.1637.

Example 3 Synthesis of 2-(trimethylsily)ethyl3,4-di-O-benzyl-2-deoxy-2-fluoro-β-L-fucopyranoside (referred to asCompound 5 hereinafter).

Compound 3 (0.277 g, 0.79 mmol) was dissolved in 1.5 ml of absolutemethanol and 8 mg (0.15 mmol) of sodium methoxide was added followed bystirring the reaction solution at room temperature for 2.5 hours underargon atmosphere. The reaction solution as such was adsorbed onAnberlite IR-120 (H Type). Elution was effected with methanol and theeluate was filtered. The filtrate was concentrated under vacuum and theresidue (0.187 g) was dissolved in 4 ml of anhydrous dimethylformamide.Under argon atmosphere, 60 mg (1.5 mmol) of oily sodium hydride (about60%) was added at 0° C. The mixture was stirred at the same temperaturefor 30 minutes and 0.26 ml (2.2 mmol) of benzyl bromide was dropwiseadded thereto at the same temperature. The mixture was reacted understirring at 0° C. for 30 minutes, heated to room temperature and stirredfor 2 hours. The reaction mixture was again cooled to 0° C. and 0.15 mlof methanol was added followed by vacuum concentration and vacuumdrying. The residue was subjected to flash chromatography with an eluentof n-hexane:ethyl acetate (8:1) to give Compound 5 (339 mg, 96.0%).

C₂₅ H₃₅ O₄ FSi (446.65)

α!_(D) ²⁵ =+19.4° (c 1.0, CHCl₃)

IR^(neat) _(max) cm⁻¹ : 1120 (ether), 860, 840 (Me₃ Si), 700 (Ph).

¹ H-NMR (CDCl₃ ; TMS): δ7.26-7.40 (m, 10H, Ph), 4.81 (ABq, 2H, CH₂ Ph),4.74 (ABq, 2H, CH₂ Ph), 4.69 (ddd, 1H, J_(F),₂ =51 Hz, J₁,₂ =J₂,₃ =7.6Hz, H-2), 4.38 (dd, J₁,₂ =7.6 Hz, J_(F),₁ =4.3 Hz, H-1), 4.00 (m, 1H,CHCH₂ Si), 3.55 (m, 1H, CHCH₂ Si), 3.65-3.55 (m, 2H, H-4, H-3), 3.48 (q,1H, J₅,₆ =6.5 Hz, H-5), 1.19 (d, 3H, J₅,₆ =6.5 Hz, H-6), 1.04 (m, 2H,CH₂ CH₂ SiMe₃).

¹⁹ F-NMR (CDCl₃ ; CFCl₃): δ-206 (dd, 1_(F), J_(F),_(2H) =51 Hz,J_(F),_(3H) =12 Hz, 2-F).

Mass spectrometry: m/z calculated for C₂₅ H₃₅ O₄ FSi 447.2366 (M+H);found 447.2356.

Example 4 Synthesis of1-O-acetyl-3,4-di-O-benzyl-2-deoxy-2-fluoro-α,β-L-fucopyranose (referredto as Compound 6 hereinafter).

Compound 5 (0.220 g, 0.493 mmol) was dissolved in 4 ml of anhydroustoluene and 0.7 ml of acetic anhydride. The solution was cooled to -30°C. under argon atmosphere, and 50 μl (0.41 mmol) of borontrifluoride-ether complex was dropwise added thereto. While stirring,the reaction mixture was heated to 0° C. over 3 hours, diluted withdichloromethane and washed with 1M aqueous sodium carbonate solution andsaturated sodium chloride aqueous solution. After drying over sodiumsulfate and vacuum concentration, the residue was subjected to flashchromatography with an eluent of n-hexane:ethyl acetate (6:1) to giveCompound 6 (α:β=1:2, 187 mg, 97.8%).

C₂₂ H₂₅ O₅ F (388.44)

IR^(neat) _(max) cm⁻¹ : 1730, 1250 (ester), 730, 700 (Ph). ¹ H-NMR(CDCl₃ ; TMS): δ 7.2-7.5 (m, 10H, Ph), 6.38 (d, 0.33H, J₁,₂ =4.0 Hz,αH-1), 5.65 (dd, 0.66H, J₁,₂ =8.0 Hz, J_(F),_(1H) =4.8 Hz, βH-1), 2.14(s, 0.66H, Ac (β)), 2.12 (s, 0.33H, Ac (α)), 1.19 (d, 2H, J₅,₆ =6.4 Hz,.βH-6), 1.16 (d, 1H, J₅,₆ =6.4 Hz, αH-6).

Example 5 Synthesis of methyl3,4-di-O-benzyl-2-deoxy-2-fluoro-1-thio-α,β-L-fucopyranose (referred toas Compound X hereinafter).

Compound 6 (0.187 g, 0.481 mmol) was dissolved in 5 ml of anhydrousdichloromethane, and 0.33 ml (2.33 mmol) of (methylthio)trimethylsilanewas added under argon atmosphere. The mixture was cooled to 0° C. and0.13 ml (1.06 mmol) of boron trifluoride-ether complex was dropwiseadded thereto. The mixture was then heated to room temperature, stirredfor 19 hours, diluted with dichloromethane, and washed with 1M aqueoussodium carbonate solution and saturated sodium chloride aqueoussolution. After drying over sodium sulfate and concentrating undervacuum, the residue was subjected to flash chromatography with an eluentof n-hexane:ethyl acetate (8:1) to yield Compound X (α:β=3:2, 133 mg,97.8%).

C₂₁ H₂₅ O₃ FS (376.50)

IR^(neat) _(max) cm⁻¹ : 1120 (ether), 730, 700 (Ph).

Mass spectrometry: m/z calculated for C₂₁ H₂₅ O₃ FS 377.1587 (M+H);found 377.1588.

α;¹ H-NMR (CDCl₃ ; TMS): δ 7.5-7.2 (m, 10H, Ph), 5.42 (d, 1H, J₁,₂ =5.7Hz, αH-1), 5.22 (ddd, 1H, J_(F),₂ =50 Hz, J₂,₃ =10 Hz, J₁,₂ =5.7 Hz,H-2), 4.81 (ABq, 2H, CH₂ Ph), 4.75 (ABq, 2H, CH₂ Ph), 4.18 (dq, 1H, J₄,₅=1.0 Hz, J₅,₆ =6.4 Hz, H-5), 3.86 (ddd, 1H, J_(F),₃ =9.3 Hz, J₂,₃ =10Hz, J₃,₄ =3.1 Hz, H-3), 3.68 (ddd, 1H, J_(F),₄ =4.3 Hz, J₃,₄ =3.1 Hz,J₄,₅ =1.0 Hz, H-4), 2.10 (s, 3H, SCH₃), 1.17 (d, 3H, J₅,₆ =6.4 Hz, H-6).

¹⁹ F-NMR (CDCl₃ ; CFCl₃): δ -198 (ddd, 1F, J_(F),_(2H) =50 Hz, J_(F),₃=9.3 Hz, J_(F),_(4H) =4.3 Hz, 2-F),

β;¹ H-NMR (CDCl₃ ; TMS): δ 7.5-7.2 (m, 10 H, Ph), 4.82 (ABq, 2H, CH₂Ph), 4.76 (ABq, 2H, CH₂ Ph), 4.76 (ddd, 1H, J_(F),₂ =51 Hz, J₁,₂ =J₂,₃=9.5 Hz, H-2), 4.34 (dd, 1H, J₁,₂ =9.5 Hz, J_(F),₁ =3.2 Hz, H-1),3.7-3.6 (m, 2H, H-3 and H-4), 3.55 (q, 1H, J₅,₆ =6.5 Hz, H-5), 2.21 (s,3H, S-CH₃), 1.22 (d, 3H, J₅,₆ =6.5 Hz, H-6).

¹⁹ F-NMR (CDCl₃ ; CFCl₃): δ -197 (ddd, 1F, J_(F),_(2H) =51 Hz,J_(F),_(3H) =13.1 Hz, J_(F),_(1H) =3.2 Hz, 2-F).

Example 6 Synthesis of 2-(trimethylsilyl)ethylO-(3,4-di-O-benzyl-2-deoxy-2-fluoro-α-L-fucopyranosyl)-(1→3)-O-(2-acetamide-4,6-O-benzylidene-2-deoxy-β-D-glucopyranosyl)-(1.fwdarw.3)-O-(2,4,6-tri-O-benzyl-β-D-galactopyranosyl)-(1→4)-2,3,6-tri-O-benzyl-β-D-glucopyranoside(referred to as Compound 8 hereinafter).

Compound X (90 mg, 0.239 mmol) and 2-(trimethylsilyl)ethylO-(2-acetamide-4,6-O-benzylidene-2-deoxy-β-D-glucopyranosyl)-(1.fwdarw.3)-O-(2,4,6-tri-O-benzyl-δ-D-galactopyranosyl)-(1→4)-2,3,6-tri-O-benzyl-β-D-glucopyranoside(referred to as Compound 7 hereinafter). (220 mg, 0.173 mmol) weredissolved in 7 ml of anhydrous benzene, and 1 g of activated MolecularSieve 4 Å was added under argon atmosphere. After stirring at roomtemperature for 8 hours, the reaction mixture was cooled to about 7° C.A mixture of 360 mg (1.39 mmol) of dimethyl(methylthio) sulfoniumtriflate and 360 mg of activated Melecular Sieve 4 Å was added theretoand the resulting reaction mixture was stirred at the same temperaturefor 1.5 hours. It was then cooled to 4° C., and 3.6 ml of methanol andthen 1.2 ml of triethylamine were added thereto. The mixture was stirredat the same temperature for 30 minutes. Insoluble materials were suctionfiltrated out and washed with dichloromethane. The filtrate and washingliquids were combined, washed with water, dried over sodium sulfate, andvacuum concentrated. The residue was subjected to flash chromatographywith an eluent of n-hexane-ethyl acetate (5:2) to yield Compound 8 (195mg, 70.4%).

C₉₄ H₁₀₈ NO₁₉ FSi (1603.0)

α!_(D) ²² =-49.0° (c 0.91, chloroform)

IR^(KBr) _(max) cm⁻¹ : 3400 (NH), 1690, 1540 (amide), 1100 (ether), 860,840 (Me₃ Si), 740, 700 (Ph).

¹ H-NMR (CDCl₃ ; TMS): δ 7.5-7.1 (m, 45H, 9Ph), 5.48 (s, 1H, PhCH), 4.92(d, 1H, J₁,₂ =3.8 Hz, H-1, fucose portion), 1.51 (s, 3H, AcN), 1.00 (m,2H, CH₂ SiMe₃), 0.73 (d, 3H, J₅,₆ =6.4 Hz, H-6,fucose portion).

¹⁹ F-NMR (CDCl₃ ; CFCl₃): δ -207 (ddd, J_(F),_(2H) =51 Hz, J_(F),_(3H)=9.7 Hz, J_(F),_(1H) =3.6 Hz, 2-F).

Mass spectrometry: m/z calculated for C₉₄ H₁₀₈ NO₁₉ FSi 1603.7381 (M+H);found 1603.7351.

Example 7 Synthesis of 2-(trimethylsilyl)ethylO-(3,4-di-O-benzyl-2-deoxy-2-fluoro-α-L-fucopyranosyl)-(1→3)-O-(2-acetamide-6-O-benzyl-2-deoxy-β-D-glucopyranosyl:-(1→3)-O-(2,4,6-tri-O-benzyl-β-D-galactopyranosyl)-(1→4)-2,3,6-tri-O-benzyl-β-D-glucopyranoside(referred to as Compound 9 hereinafter).

Compound 8 (125 mg, 0.0779 mmol) was dissolved in 2.5 ml of anhydroustetrahydrofuran and 400 mg of activated Molecular Sieve 4 Å was addedunder argon atmosphere. After stirring the mixture at room temperaturefor 1 hour, 74 mg (1.18 mmol) of sodium borohydrocyanide was addedthereto at the same temperature. After cooling the mixture to 0° C.,1.75 ml (1.75 mmol) of 1M hydrochloric acid-ether solution was dropwiseadded thereto under argon atmosphere. After heating the mixture to roomtemperature, stirring was continued for 20 minutes and 15 ml ofdichloromethane and 3 ml of water were added thereto. Insolublematerials were filtered out and washed with dichloromethane. Thefiltrate and washing liquids were combined, washed with 2M aqueoushydrochloric acid solution and then with water, and dried over sodiumsulfate. After vacuum concentration, the residue was subjected to flashchlomatography with an eluent of n-hexane:ethyl acetate (3:2) to yieldCompound 9 (95 mg, 76.0%).

C₉₄ H₁₁₀ NO₁₉ FSi (1605.0)

α!_(D) ²² =-19.5° (c 1.12, chloroform)

IR^(KBr) _(max) cm⁻¹ : 3700-3200 (OH, NH), 1660, 1500 (amide), 1070(ether), 860, 840 (Me₃ Si), 740, 700 (Ph).

¹ H-NMR (CDCl₃ ; TMS): δ 7.5-7.0 (m, 45H, 9Ph), 1.51 (s, 3H, AcN), 1.14(d, 3H, J₅,₆ =6.4 Hz, H-6, fucose portion), 1.01 (m, 2H, CH₂ SiMe₃).

¹⁹ F-NMR (CDCl₃ ; CFCl₃): δ -208 (dd, J_(F),_(2H) =54 Hz, J_(F),_(3H)=6.5 Hz, 2-F).

Mass spectrometry: m/z calculated for C₉₄ H₁₁₀ NO₁₉ FSi 1605.7537 (M+H);found 1605.7520.

Example 8 Synthesis of 2-(trimethylsilyl)ethyl O-(methyl5-acetamide-4,7,8,9-tetra-O-acetyl-3,5-dideoxy-D-glycero-α-D-galacto-2-nonuropyranosylonate)-(2→3)-O-(2,4,6--tri-O-benzoyl-β-D-galactopyranosyl)-(1→4)-O-(3,4-di-O-benzyl-2-deoxy-2-fluoro-α-L-fucopyranosyl)-(1→3)!-O-(2-acetamide-6-O-benzyl-2-deoxy-β-D-glucopyranosyl)-(1→3)-O-(2,4,6-tri-O-benzyl-β-D-galactopyranosyl)-(1→4)-2,3,6-tri-O-benzyl-α-D-glucopyranoside(referred to as Compound 11 hereinafter).

Compound 9 (157 mg, 0.0978 mmol) and methyl O-(methyl5-acetamide-4,7,8,9-tetra-O-acetyl-3,5-dideoxy-D-glycero-α-D-galacto-2-nonuropyranosylonate)-(2→3)-2,4,6-tri-O-benzoyl-1-thio-β-D-galactopyranoside(Compound 10) (134 mg, 0.135 mmol) were dissolyed in 5 ml of anhydrousdichloromethane and 320 mg of Molecular Sieve 4 Å was added under argonatmosphere. After stirring the mixture at room temperature for 4 hours,100 mg (0.387 mmol) of dimethyl(methylthio)sulfonium triflate and 100 mgof activated Molecular Sieve 4 Å were added at the same temperature. Thereaction mixture was stirred under argon atmosphere at the sametemperature for 22 hours. It was cooled with ice and 0.36 ml of methanoland 0.18 ml of triethylamine were added. The mixture was stirred at thesame temperature for 30 minutes. After dilution with dichloromethane,filtration and washing, the filtrate and washing liquids were combinedand washed with water. After drying over sodium sulfate andconcentration under vacuum, the residue was subjected to flashchromatography with an eluent of n-hexane:ethyl acetate (1:3) to yieldCompound 11 (98 mg, 39.3%).

C₁₄₁ H₁₅₉ N₂ O₃₉ FSi (2552.9)

α!_(D) ²⁴ =-13.7° (c 1.25, chloroform)

IR^(KBr) _(max) cm⁻¹ : 3400 (NH), 1740, 1270 (ester), 1690, 1500(amide), 1070 (ether), 860, 840 (Me₃ Si), 740, 710 (Ph).

¹ H-NMR (CDCl₃ ; TMS): δ 8.3-7.0 (m, 60H, 12Ph), 5.67 (m, 1H, H-8,sialic acid portion), 5.43 (dd, 1H, J₁,₂ =8.2 Hz, J₂,₃ =9.9 Hz, H-2,galactose portion), 5.30 (broad d, 1H, J₃,₄ =J₄,₅ =3.5 Hz, H-2,galactose portion), 5.23 (dd, 1H, J₇,₈ =12.4 Hz, J₆,₇ =2.6 Hz, H-7,sialic acid portion), 3.78 (s, 3H, OCH₃), 2.43 (dd, 1H, J_(3e),_(3a)=12.7 Hz, J_(3e),₄ =4.6 Hz, H-3e, sialic acid portion), 2.14, 1.95,1.92, 1.80 (4s, 12H, 4AcO), 1.53, 1.50 (2s, 6H, 2AcN), 1.09 (d, 3H, J₅,₆=6.4 Hz, H-6, sialic acid portion), 1.01 (m, 2H, Me₃ SiCH₂ CH₂ O).

¹⁹ F-NMR (CDCl₃ ; CFCl₃): δ -208 (dd, J_(F),_(2H) =53 Hz, J_(F),_(3H)=7.0 Hz, 2-F).

Mass spectrometry: m/z calculated for C₁₄₁ H₁₅₉ N₂ O₃₉ FSi 2553.0385(M+H); found 2553.0404.

Example 9 Synthesis of 2-(trimethylsilyl)ethyl O-(methyl5-acetamide-4,7,8,9-tetra-O-acetyl-3,5-dideoxy-D-glycero-α-D-galacto-2-nonuropyranosylonate)-(2→3)-O-(2,4,6-tri-O-benzoyl-β-D-galactopyranosyl)-(1→4)-O-(3,4-di-O-acetyl-2-deoxy-2-fluoro-α-L-fucopyranosyl)-(1→3)!-O-(2-acetamide-6-O-acetyl-2-deoxy-β-D-glucopyranosyl)-(1→3)-O-(2,4,6-tri-O-acetyl-β-D-galactopyranosyl)-(1→4)-2,3,6-tri-O-acetyl-β-D-glucopyranoside(referred to as Compound 12 hereinafter).

Compound 11 (98 mg, 0.038 mmol) was dissolved in 15 ml of ethanol and5.5 ml of acetic acid, and catalytic reduction was effected in thepresence of 90 mg of 10% palladium-carbon under normal hydrogen pressurefor 4 days while heating at 45° C. After filtration and vacuumconcentration of solvent, 4 ml of pyridine and 2 ml of acetic anhydridewere added to the residue and the mixture was stirred at roomtemperature for 20 hours. After vacuum concentration, the residue wassubjected to flash chromatogaphy with an eluent of n-hexane:ethylacetate (1:6) to yield Compound 12 (66.6 mg, 81.8%).

C₉₆ H₁₂₃ N₂ O₄₈ FSi (2120.1)

α!_(D) ²³ =-23.2° (c 0.73, chloroform)

IR^(KBr) _(max) cm⁻¹ : 3400 (NH), 1740, 1230 (ester), 1700, 1530(amide), 1070 (ether), 860, 840 (Me₃ Si), 720 (Ph).

¹ H-NMR (CDCl₃ ; TMS): δ 8.2-7.4 (m, 15H, 3Ph), 5.66 (m, 1H, H-8, sialicacid portion), 5.27 (dd, 1H, J₆,₇ =2.9 Hz, J₇,₈ =9.9 Hz, H-7, sialicacid portion), 5.35 (d, 1H, J₁,₂ =3.3 Hz, H-1, fucose portion), 5.15(dd, 1H, J₂,₃ =J₃,₄ =9.3 Hz, H-3, glucose portion), 4.46 (d, 1H, J₁,₂=7.9 Hz, H-1, glucose portion), 3.80 (s, 3H, OCH₃), 3.45 (dd, 1H, J₂,₃=10.0 Hz, J₃,₄ =3.5 Hz, H-3, galactose portion), 2.41 (dd, 1H,J_(3a),_(3e) =12.7 Hz, J_(3e),₄ =4.7 Hz, H-3e, sialic acid portion),2.13, 2.10, 2.09, 2.08, 2.07, 2.07, 2.06, 2.03, 2.02, 2.00, 1.93, 1.91,0.91 (13s, 39H, 13AcO), 1.78, 1.56 (2s, 6H, 2AcN), 1.09 (d, 3H, J₅,₆=6.5 Hz, H-6, fucose portion), 0.90 (m, 2H, Me₃ SiCH₂ CH₂ O).

¹⁹ F-NMR (CDCl₃ ; CFCl₃): δ -208 (ddd, J_(F),_(2H) =50 Hz, J_(F),_(3H)=7.6 Hz, J_(F),_(1H) =2.5 Hz, 2-F).

Mass spectrometry: m/z calculated for C₉₆ H₁₂₃ N₂ O₄₈ FSi 2120.7110(M+H); found 2120.7072.

Example 10 Synthesis of O-(methyl5-acetamide-4,7,8,9-tetra-O-acetyl-3,5-dideoxy-D-glycero-α-D-galacto-2-nonuropyranosylonate)-(2→3)-O-(2,4,6-tri-O-benzoyl-β-D-galactopyranosyl)-(1→4)-O-(3,4-di-O-acetyl-2-deoxy-2-fluoro-α-L-fucopyranosyl)-(1→3)!-O-(2-acetamide-6-O-acetyl-2-deoxy-β-D-glucopyranosyl)-(1→3)-O-(2,4,6-tri-O-acetyl-β-D-galactopyranosyl)-(1→4)-2,3,6-tri-O-acetyl-D-glucopyranoside(referred to as Compound 13 hereinafter).

Under argon atmosphere, 60 mg (0.028 mmol) of Compound 12 was dissolvedin 0.8 ml of anhydrous dichloromethane. The solution was cooled to 0° C.and 1.6 ml of trifluoroacetic acid was dropwise added thereto. Afterstirring at the same temperature for 5 hours, 2 ml of ethyl acetate wasadded and the mixture was concentrated at the same temperature underreduced pressure and then vacuum. The residue was subjected to silicagel column chromatography with eluents of dichloromethane todichloromethane-methanol (30:1 to 20:1) to yield Compound 13 (49.0 mg,85.7%).

C₉₁ H₁₁₁ N₂ O₄₈ F (2019.8)

α!_(D) ²⁵ =-9.4° (c 0.75, chloroform)

IR^(KBr) _(max) cm⁻¹ : 3600-3200 (OH, NH), 1740, 1230 (ester), 1670,1540 (amide), 1070 (ether), 720 (Ph).

Mass spectrometry: m/z calculated for C₉₁ H₁₁₁ N₂ O₄₈ F 2020.6402 (M+H);found 2020.6392.

Example 11 Synthesis of O-(methyl5-acetamide-4,7,8,9-tetra-O-acetyl-3,5-dideoxy-D-glycero-α-D-galacto-2-nonuropyranosylonate)-(2→3)-O-(2,4,6-tri-O-benzoyl-β-D-galactopyranosyl)-(1→4)-O-(3,4-di-O-acetyl-2-deoxy-2-fluoro-α-L-fucopyranosyl)-(1→3)!-O-(2-acetamide-6-O-acetyl-2-deoxy-β-D-glucopyranosl)-(1→3)-O-(2,4,6-tri-O-acetyl-β-D-galactopyranosyl)-(1.fwdarw.4)-2,3,6-tri-O-acetyl-α-D-glucopyranosyltrichloroacetoimidate (referred to as Compound 14 hereinafter).

After dissolying 49.0 mg (0.0242 mmol) of Compound 13 in 3 ml ofanhydrous dichloromethane, the solution was cooled to 0° C. under argonatmosphere. 0.1 ml (0.997 mmol) of trichloroacetonitrile and then 3 μl(0.02 mmol) of 1,8-diazabicyclo 5.4.0!undec-7-ene (DBU) were addedthereto and the mixture was stirred at the same temperature for 3 hours.After vacuum concentration, the residue was subjected to silica gelcolumn chromatography with eluents of dichloromethane todichloromethane-methanol (40:1 to 20:1) to yield Compound 14 (45.0 mg,85.9%).

C₉₃ H₁₁₁ N₃ O₄₈ Cl₃ F (2164.2)

α!_(D) ²³ =-0.83° (c 0.69, chloroform)

IR^(KBr) _(max) cm⁻¹ : 3400 (NH=C), 1740, 1230 (ester), 1680, 1540(amide), 1070 (ether), 760, 720 (Ph).

¹ H-NMR (CDCl₃ ; TMS): δ 8.65 (s, 1H, NH=C), 8.2-7.4 (m, 15H, 3Ph), 6.47(d, 1H, J₁,₂ =3.7 Hz, H-1, glucose portion), 5.66 (m, 1H, H-8, sialicacid portion), 5.36 (d, 1H, J₁,₂ =3.8 Hz, H-1, fucose portion), 5.28(dd, 1H, J₆,₇ =2.7 Hz, J₇,₈ =9.9 Hz, H-7, sialic acid portion), 3.81 (s,3H, OCH₃), 3.48 (dd, 1H, J₂,₃ =9.9 Hz, J₃,₄ =4.0 Hz, H-3, galactoseportion), 2.41 (dd, 1H, J_(3a),_(3e) =12.7 Hz, J_(3e),₄ =4.4 Hz, H-3e,sialic acid portion), 2.14, 2.10, 2.10, 2.08, 2.07, 2.07, 2.04, 2.03,2.00, 1.96, 1.93, 1.92, 1.91 (13s, 39H, 13AcO), 1.78, 1.56 (2s, 6H,2AcN), 1.10 (d, 3H, J₅,₆ =6.5 Hz, H-6, fucose portion), 0.90 (m, 2H, Me₃SiCH₂ CH₂ O).

¹⁹ F-NMR (CDCl₃ ; CFCl₃): δ -209 (dd, J_(F),_(2H) =54 Hz, J_(F),_(3H)=10 Hz, 2-F).

Mass spectrometry: m/z calculated for C₉₃ H₁₁₁ N₃ O₄₈ Cl ₃ F 2163.5498(M+H); found 2163.5454.

Example 12 Synthesis of O-(methyl5-acetamide-4,7,8,9-tetra-O-acetyl-3,5-dideoxy-D-glycero-α-D-galacto-2-nonuropyranosylonate)-(2→3)-O-(2,4,6-tri-O-benzoyl-β-D-galactopyranosyl)-(1→4)-O-(3,4-di-O-acetyl-2-deoxy-2-fluoro-α-L-fucopyranosyl)-(1→3)!-O-(2-acetamide-6-O-acetyl-2-deoxy-β-D-glucopyranosyl)-(1→3)-O-(2,4,6-tri-O-acetyl-β-D-galactopyranosyl)-(1→4)-2,3,6-tri-O-acetyl-.beta.-D-glucopyranosyl)-(1→1)-(2S,3R,4E)-2-azide-3-O-benzoyl-4-octadecene-1,3-diol(referred to as Compound 15 hereinafter).

After dissolving 45 mg (0.021 mmol) of Compound 14 and 20 mg (0.047mmol) of (2S,3R,4E)-2-azide-3-O-benzoyl-4-octadecene-1,3-diol (CompoundA) in 1.5 ml of anhydrous dichloromethane, 0.45 g of activated MolecularSieve 4 Å was added. The mixture was stirred under argon atmosphere atroom temperature for 30 minutes and cooled to 0° C. Borontrifluoride-ether complex (0.012 ml, 0.10 mmol) was added and themixture was stirred at the same temperature for 3 hours. After dilutionwith dichloromethane, insoluble materials were filtered out and washedwith dichloromethane and the filtrate and washing liquids were combined.The organic layer was washed with 1M aqueous sodium bicarbonate solutionand then with saturated sodium chloride aqueous solution, and dried oversodium sulfate. After vacuum concentration, the residue was subjected tosilica gel column chromatography with eluents of dichloromethane todichloromethane-methanol (50:1 to 30:1) to yield Compound 15 (36 mg,71.5%).

C₁₁₆ H₁₄₈ N₅ O₅₀ F (2431.5)

α!_(D) ²³ =-24.8° (c 1.13, chloroform)

IR^(KBr) _(max) cm⁻¹ : 2950, 2850 (methyl, methylene), 2100 (azide),1750, 1230 (ester), 1680, 1550 (amide), 1070 (ether), 800, 720 (Ph).

¹ H-NMR (CDCl₃ ; TMS): δ 8.2-7.4 (m, 15H, 3Ph), 5.91 (dt, 1H, J₄,₅ =15.2Hz, J₅,₆ =6.6 Hz, H-5, sphingosine portion), 5.67 (m, 1H, H-8, sialicacid portion), 5.35 (d, 1H, J₁,₂ =3.1 Hz, H-1, fucose portion), 5.27(dd, 1H, J₆,₇ =2.7 Hz, J₇,₈ =9.9 Hz, H-7, sialic acid portion), 5.14(dd, 1H, J₂,₃ =J₃,₄ =9.2 Hz, H-3, glucose portion), 4.49 (d, 1H, J₁,₂=7.7 Hz, H-1, glucose portion), 3.80 (s, 3H, OCH₃), 3.44 (dd, 1H, J₂,₃=10.3 Hz, J₃,₄ =3.6 Hz, H-3, galactose portion), 2.40 (dd, 1H,J_(3a),_(3e) =12.5 Hz, J_(3e),₄ =4.4 Hz, H-3e, sialic acid portion),2.14, 2.11, 2.08, 2.08, 2.07, 2.07, 2.06, 2.04, 2.02, 2.01, 1.94, 1.91,1.91 (13s, 39H, 13AcO), 1.79, 1.56 (2s, 6H, 2AcN), 1.27 (s, 22H, 11CH₂),1.10 (d, 3H, J₅,₆ =6.5 Hz, H-6, fucose portion), 0.87 (t, 3H, J=6.6 Hz,CH₃ CH₂).

¹⁹ F-NMR (CDCl₃ ; CFCl₃): δ -208 (dd, J_(F),_(2H) =51 Hz, J_(F),_(3H)=10Hz, 2-F).

Mass spectrometry: m/z calculated for C₁₁₆ H₁₄₈ N₅ O₅₀ F 2431.9288(M+H); found 2431.9258.

Example 13 Synthesis of O-(methyl5-acetamide-4,7,8,9-tetra-O-acetyl-3,5-dideoxy-D-glycero-α-D-galacto-2-nonuropyranosylonate)-(2→3)-O-(2,4,6-tri-O-benzoyl-β-D-galactopyranosyl)-(1→4)-O-(3,4-di-O-acetyl-2-deoxy-2-fluoro-α-L-fucopyranosyl)-(1→3)!-O-(2-acetamide-6-O-acetyl-2-deoxy-β-D-glucopyranosyl)-(1→3)-O-(2,4,6-tri-O-acetyl-β-D-galactopyranosyl)-(1→4)-2,3,6-tri-O-acetyl-β-D-glucopyranosyl)-(1→1)-(2S,3R,4E)-3-O-benzoyl-2-tetracosanamide-4-octadecene-1,3-diol(referred to as Compound 16 hereinafter).

Compound 15 (43 mg, 0.018 mmol) was dissolved in a mixed solvent of 4.17ml of pyridine and 0.83 ml of water and the solution was cooled to 0° C.Hydrogen sulfide gas was passed through the solution for 60 hours.Nitrogen gas was passed through the solution for 10 minutes to removehydrogen sulfide remaining in the solution. The concentrated residuefrom the solution was dissolved in 2 ml of anhydrous dichloromethane andcooled to 0° C. Tetracosanoic acid (13 mg, 0.035 mmol) and then1-ethyl-3-(3-dimethylaminopropyl)carbodiimide, hydrochloride (10 mg,0.050 mmol) were added and the mixture was stirred at room temperaturefor 15 hours. It was diluted with dichloromethane, washed with water anddried over sodium sulfate. After vacuum concentration, the residue wassubjected to silica gel chromatography with eluents of dichloromethaneto dichloromethane-methanol (50:1 to 30:1) to yield Compound 16 (32 mg,66.0%).

C₁₄₀ H₁₉₆ N₃ O₅₁ F (2756.1)

α!_(D) ²⁴ =-15.3° (c 0.83, chloroform)

IR^(KBr) _(max) cm⁻¹ : 3400 (NH), 2950, 2850 (methyl, methylene), 1750,1230 (ester), 1680, 1530 (amide), 1070 (ether), 810, 710 (Ph).

¹ H-NMR (CDCl₃ ; TMS): δ8.2-7.4 (m, 15H, 3Ph), 5.85 (dt,1H, J₄,₅ =14.1Hz, J₅,₆ =6.9 Hz, H-5, sphingosine portion), 5.66 (m, 1H, H-8, sialicacid portion), 5.35 (d, 1H, J₁,₂ =2.8 Hz, H-1, fucose portion), 5.27(dd, 1H, J₆,₇ =2.8 Hz, J₇,₈ =9.8 Hz, H-7, sialic acid portion), 5.14(dd, 1H, J₂,₃ =J₃,₄ =9.3 Hz, H-3, glucose portion), 4.43 (d, 1H, J₁,₂=7.7 Hz, H-1, glucose portion), 3.80 (s, 3H, OCH₃), 3.43 (dd, 1H, J₂,₃=10.0Hz, J₃,₄ =3.6 Hz, H-3, galactose portion), 2.41 (dd, 1H,J_(3a),_(3e) =12.7 Hz, J_(3e),₄ =4.7 Hz, H-3e, sialic acid portion),2.13, 2.10, 2.07, 2.07, 2.07, 2.05, 2.01, 2.00, 2.00, 1.93, 1.93, 1.90,1.90 (13s, 39H, 13AcO), 1.78, 1.56 (2s, 6H, 2AcN), 1.26 (s, 64H, 32CH₂),1.10 (d, 3H, J₅,₆ =6.4 Hz, H-6, fucose portion), 0.87 (t, 6H, J=6.6 Hz,2CH₃ CH₂).

¹⁹ F-NMR (CDCl₃ ; CFCl₃): δ -208 (dd, J_(F),_(2H) =50 Hz, J_(F),_(3H)=11 Hz, 2-F).

Mass spectrometry: m/z calculated for C₁₄₀ H₁₉₆ N₃ O₅₁ F 2756.2932(M+H); found 2756.2867.

Example 14 Synthesis ofO-(5-acetamide-3,5-dideoxy-D-glycero-α-D-galacto-2-nonuropyranosylonicacid)-(2→3)-O-β-D-galactopyranosyl-(1→4)-O-(2-deoxy-2-fluoro-α-L-fucopyranosyl-(1→3)!-O-(2-acetamide-2-deoxy-β-D-glucopyranosyl)-(1→3)-O-β-D-galactopyranosyl-(1→4)-.beta.-D-glucopyranosyl-(1→1)-(2S,3R,4E)-2-tetracosanamide-4-octadecene-1,3-diol(referred to as Compound IX hereinafter).

Compound 16 (33.0 mg, 0.0119 mmol) was dissolved in 2 ml of absolutemethanol and 10 mg (0.19 mmol) of sodium methoxide was added under argonatmosphere at room temperature. The mixture was stirred at 40° C. for 24hours. After allowing it to cool at room temperature, 0.18 ml of waterwas added and the mixture was stirred for 8 hours. It was passed througha layer of Amberlite IR-120 (H-type) with an eluent of methanol. Aftervacuum concentration, the residue was subjected to gel filtration columnchromatography on Sephadex LH20 (15 g) using chloroform-methanol-water(50:40:7) as an eluent to yield Compound IX (20.6 mg, 66.0%).

C₈₅ H₁₅₂ N₃ O₃₄ F (1779.2)

α!_(D) ²⁴ =-16.0° (c 0.35, chloroform-methanol-H₂ O=50:40:7)

IR^(KBr) _(max) cm⁻¹ : 3700-3200 (OH, NH), 2920, 2850 (methyl,methylene), 1700 (carboxylic acid), 1650, 1540 (amide), 1070 (ether).

¹ H-NMR (CD₃)₂ SO--D₂ O=50:1; TMS!: δ 5.32 (dt,1H, J₄,₅ =15.3 Hz, J₅,₆=6.6 Hz, H-5, sphingosine portion), 5.34 (dd, 1H, J₃,₄ =7.3 Hz, J₄,₅=15.3 Hz, H-4, sphingosine portion), 5.10 (d, 1H, J₁,₂ =3.5 Hz, H-1,fucose portion), 4.74 (d, 1H, J₁,₂ =6.8 Hz, H-1, N-acetyl-glucosamineportion), 4.16 (d, 1H, J₁,₂ =7.8 Hz, glucose portion), 2.77 (dd, 1H,J_(3a),_(3e) =12.2 Hz, J_(3e),₄ =4.8 Hz, H-3e, sialic acid portion),1.89, 1.78 (2s, 6H, 2AcN), 1.23 (s, 64H, 32CH₂), 0.96 (d, 3H, J₅,₆ =6.3Hz, H-6, fucose portion), 0.85 (t, 6H, J=6.4 Hz, 2CH₃ CH₂).

¹⁹ F-NMR (CD₃)₂ SO--D₂ O=50:1; CFCl₃ !: δ -208 (dd, J_(F),_(2H) =54 Hz,J_(F),_(3H) =8 Hz, 2-F).

Mass spectrometry: m/z calculated for C₈₅ H₁₅₂ N₃ O₃₄ F 1801.0139(M+Na); found 1801.0167. elemental analysis: calculated for C₈₅ H₁₅₂ N₃O₃₄ F.2.5H₂ O.1.75CHCl₃ C: 51.25, H: 7.87, N: 2.07; found C: 51.18, H:8.17, N: 2.16.

What is claimed is:
 1. A compound represented by the formula (I-1):##STR20## wherein R denotes an aliphatic acyl group having 2 to 6 carbonatoms; R¹ denotes a hydrogen atom or a lower alkyl group having 1 to 5carbon atoms; R²⁰, R³⁰ and R⁵ independently denote a hydrogen atom, analiphatic acyl group having 2 to 6 carbon atoms, or an aromatic acylgroup having 7 to 13 carbon atoms; R⁴ denotes a hydroxy group, analiphatic acylamino group having 2 to 6 carbon atoms, an aromaticacylamino group having 7 to 13 carbon atoms, an aliphatic acyloxy grouphaving 2 to 6 carbon atoms, or an aromatic acyloxy group having 7 to 13carbon atoms; Ra denotes a straight or branched, saturated orunsaturated, aliphatic group having 1 to 30 carbon atoms; Me denotes amethyl group; and n denotes an integer of 0 to 20, provided that when R¹is a hydrogen atom, R²⁰, R³⁰ and R⁵ all denote a hydrogen atom; and R⁴denotes a hydroxy group, or an aliphatic or aromatic acylamino group; orwhen R¹ is a lower alkyl group, R²⁰, R³⁰ and R⁵ denote an aliphatic oraromatic acyl group; and R⁴ denotes an aliphatic or aromatic acylaminogroup, or an aliphatic or aromatic group.
 2. A compound represented bythe formula (I-2): ##STR21## wherein R, R¹, R²⁰, R³⁰, R⁴, R⁵, Me and nare as defined in claim 1; and R¹⁰ denotes a N₃ or NH₂ group, providedthat when R¹ is a hydrogen atom, R²⁰, R³⁰ and R⁵ all denote a hydrogenatom; and R⁴ denotes a hydroxy group, or an aliphatic or aromaticacylamino group; or when R¹ is a lower alkyl group, R²⁰, R³⁰ and R⁵denote an aliphatic or aromatic acyl group; and R⁴ denotes an aliphaticor aromatic acylamino group, or an aliphatic or aromatic acyloxy group.3. A compound represented by the formula (II): ##STR22## wherein R, R¹,R²⁰, R³⁰, R⁴ and Me are as defined in claim 1; and X denotes a hydroxygroup, a fluorine atom, a thioalkyl group having 1 to 5 carbon atoms, athioaryl group having 6 to 12 carbon atoms, or a --OC (NH) CCl₃ group,provided that when R¹ is a hydrogen atom, R²⁰ and R³⁰ both denote ahydrogen atom; R⁴ denotes a hydroxy group, or an aliphatic or aromaticacylamino group; and X denotes a hydroxy group; or when R¹ is a loweralkyl group, R²⁰ and R³⁰ denote an aliphatic or aromatic acyl group; R⁴denotes an aliphatic or aromatic acylamino group, or an aliphatic oraromatic acyloxy group; and X denotes a fluorine atom, a thioalkylgroup, a thioaryl group or a --OC(NH)CCl₃ group.
 4. A compoundrepresented by the formula (III): ##STR23## wherein R, R¹, R⁴ and Me areas defined in claim 1 ; R²¹ and R³¹ independently denote a hydrogenatom, an unsubstituted or substituted phenylmethyl group having 7 to 13carbon atoms, an aliphatic acyl group having 2 to 6 carbon atoms, or anaromatic acyl group having 7 to 18 carbon atoms; and TAS denotes atrialkylsilyl group in which the alkyl group has 1 to 7 carbon atoms,provided that when R¹ is a hydrogen atom, R²¹ and R³¹ both denote ahydrogen atom; and R⁴ denotes a hydroxy group or an aliphatic oraromatic acylamino group; or when R¹ is a lower alkyl group, R²¹ and R³¹denote an unsubstituted or substituted phenylmethyl group, or analiphatic or aromatic acyl group; and R⁴ denotes an aliphatic oraromatic acylamino group, or an aliphatic or aromatic acyloxy group. 5.A compound represented by the formula (IV): ##STR24## wherein R²¹, R⁴and TAS are as defined in claim 4, provided that when R²¹ is a hydrogenatom, R⁴ denotes a hydroxy group, or an aliphatic or aromatic acylaminogroup; or when R²¹ is an aliphatic or aromatic acyl group, or anunsubstituted or substituted phenylmethyl group, R⁴ denotes an aliphaticor aromatic acylamino group, or an aliphatic or aromatic acyloxy group.6. A compound represented by the formula (V): ##STR25## wherein R²¹, R⁴and TAS are as defined in claim 4; and Ph denotes an unsubstituted orsubstituted phenyl group, provided that when R²¹ is a hydrogen atom, R⁴denotes a hydroxy group, or an aliphatic or aromatic acylamino group; orwhen R²¹ is an unsubstituted or substituted phenylmethyl group, or analiphatic or aromatic acyl group, R⁴ denotes an aliphatic or aromaticacylamino group, or an aliphatic or aromatic acyloxy group.
 7. Acompound represented by the formula (VI): ##STR26## wherein R⁶ denotesan unsubstituted or substituted phenylmethyl group; and R⁹ denotes alower alkyl group having 1 to 5 carbon atoms, or an unsubstituted orsubstituted phenyl group having 6 to 12 carbon atoms.
 8. A process forpreparing a compound represented by the formula (VIII): ##STR27##wherein R⁸ denotes an aliphatic acyl group having 2 to 6 carbon atoms oran aromatic acyl group having 7 to 13 carbon atoms,comprising reacting acompound represented by the formula: ##STR28## wherein R⁸ is as definedabove, with hydrogen bromide in the presence of acetic acid; or withphosphorus tribromide or phosphorous pentabromide.